A parallel processing system is sometimes used to speed up calculation processing by a computer. In the parallel processing system, processes are executed in parallel by a plurality of computers. As the parallel processing system, a shared memory type parallel processing system and a distributed memory type parallel processing system are known.
FIG. 1A is a conceptual diagram showing an example of the shared memory type parallel processing system. As shown in FIG. 1A, the parallel processing system 100 is composed of a plurality of computers 102 (102-1 to 102-n) and a shared memory 101. In the parallel processing system 100, a plurality of processes are respectively allocated to the plurality of computers 102 (102-1 to 102-n). Each of the plurality of computers 102 executes the allocated process while accessing the shared memory 101.
On the other hand, FIG. 1B is a conceptual diagram showing an example of the distributed memory type parallel processing system. As shown in FIG. 1B, the parallel processing system 100 is composed of a plurality of computers 102-1 to 102-n. The distributed memories 103 (103-1 to 103-n) are respectively provided for the computers 102. Each computer 102 executes the allocated process while accessing the distributed memory 103. In the parallel processing system 100, the synchronization processing is required to equalize the data stored in the distributed memories 103 among the plurality of computers 102. That is, when the execution of the allocated process ends in each computer 102, communication is carried out among the plurality of computers 102 to copy a processing result stored in the distributed memory 103 of each computer 102 to the distributed memories 103 of the other computers 102. After that, each computer 102 executes a process allocated next.
A related technique is disclosed in Patent Literature 1 (Japanese Patent No. 2,559,918), in which a plurality of computers independently operating are connected to configure the distributed memory type parallel processing system. The distributed memory type parallel processing system is composed of a synchronization request register section configured to issue a synchronization request from each computer independently and hold a synchronization request signal; a synchronization determining section configured to determine the synchronization request signals from the synchronization request register sections of all the computers; a synchronization distributing section configured to distribute the determination result to all the computers; a synchronization detection register section configured to perform synchronization detection from the distributed determination results; a status request register section provided for each computer, to independently issue a status request of whether each computer executes a process in a predetermined manner, and to hold a status request signal; a status determining section to determine whether the status request signals from all the status request registers of all the computers are present; a status distributing section configured to distribute the determination result to all the computers; and a status detection register section to carry out a status detection based on the determination result distributed from the status distributing section and the determination result distributed from the synchronization distributing section. Thus, the statuses of all the computers can be detected when the synchronization is established among all the computers.